What are the advantages and disadvantages of chain and belt drive trains is terms of durability and maintenances costs? Also, the recirculating ball and nut verses rack and pinion.
Lastly, the common rail direct fuel injection versus the electrical fuel injection turbo diesel. What are their advantages in term of performance and cost of maintenance plus fuel economy?
You cannot expect a detailed reply to such technical questions and so I will only give you a brief reply to eaach:
1. To my mind, the chain drive is better than a belt drive for the camshafts. Also chains do not snap without warning and last for almost forever. However the chain is noisy and it is more complicated to keep it in good tension.
Belts on the other hand are much quieter but must be replaced at regular intervals or else you could end up with very bent valves and even a scrap engine. Belts are not cheap and usually replacing the belt also entails replacing the idlers and their bearings which can come up to quite a hefty sum.
2. The recirculating ball steering tends to be quieter and does not require as frequent adjustment as the rack and pinion. Rack and pinion steerings have very limited adjusments and once that is taken up, the rack can make all sorts of noises. Rack and pinion power steering units also have a higher tendency for leakage.
3. I think you are talking about a common rail system as opposed to a unit injector system.
I would prefer the common rail system for its efficiency and fuel consumption, although the operating pressures are much higher and there is a need to ensure that fuel used is clean.